A Wii or computer game on the RNA world would be fantastic and I wish I was a game developer! How much fun would it be to control RNA molecules to fight invading viruses, but not destroy the cell in doing so…ok maybe this game would have too limited a distribution.

The RNA world is a term coined originally to describe a stage in the earliest development of life. Because RNA as a molecule can store genetic information (like DNA) and perform catalytic reactions (like proteins do), it is believed that this molecule kept life going before the establishment of the DNA-> protein system we see in today’s cells. Another fact supporting this idea is that DNA requires proteins to replicate, and proteins require DNA as a storage molecule; DNA and proteins need each other so neither alone could have been an effective genetic material. RNA can do it (experiments in the laboratory have shown this). The phrase 'RNA world' can be blamed on Walter Gilbert in 1986 but the concept of an early RNA stage of life has been around since 1968 (according to Wikipedia), but more realistically probably since molecular evolutionists put their heads together to look at early life from a non-protein angle.

Many textbooks forget that having RNA alone is a hypothetical concept. In reality, there would have been amino acids (the building blocks of proteins) and short peptides (a few amino acids but not catalytic) as well as metal ions and other chemical compounds. We can see the possible effect these compounds would have had on the evolution of the present genetic system. Non-coding RNAs today commonly use metal ions for stability and RNA is never alone in the cell; it always binds to proteins.  

The term RNA world is also being applied to today’s cells since RNA plays a prominent role in cellular activities. Part of that may be a reflection on the ancient nature of many RNA-based mechanisms, or how quickly RNA can evolve (when compared to DNA and proteins). I will go into the reasons why RNA was for decades, the forgotten molecule and why it has come into prominence again in another blog.

Wonderful image of the RNA world by Julie Newdoll